The case for electrifying the Chiltern mainline

[Tobbes]

The tunnels - I don’t know the detail. However I do know that conductor bar is very, very, expensive, and slab track even more so. The latter is also extremely disruptive to install - with possessions measured in weeks and months rather than hours. (I’ve been in three seperate tunnels when slab was being installed, it’s precise Business with no room for error)

Menanhwile battery hybrid EMUs are already in service elsewhere in Europe, and design for them in this country is well underway. It’s reasonable to assume that within 5 years most of not all EMUs on the market will come with a traction battery option. The cost of a traction battery for use in this circumstance is unlikely to be more than a few hundred thousand for a 4 car unit, which will be comfortably less than the infrastructure work it saves. And a traction battery has all sorts of other performance benefits, not least enabling trains to keep moving for a while when the power is off unexpectedly.

Fair enough, thanks very much, @Bald Rick .

 

[The Planner]

Moving the XX33 to replace the xx39 at New Street would allow XC to run both via Coventry.

No it doesn't. If it was that easy XC would be doing it now.

 

[si404]

I'd divert those services that run via the Met to Baker Street as LUL S8 services.

We'll ignore that the Met doesn't have the track capacity to handle the and just continue treating that line as an aside.

Again: If having a short section of adjacent track with a different electrification is something that pushes back electrification of the Birmingham suburban routes, why isn't it a problem for the London suburban routes?

Phase 2 would cover the Cotswold Line into Worcester (with Hereford-Shrub Hill getting handed to the Turbos from/to Bristol.)

(Oxford-Worcester is off-topic for this thread, but I'm developing a point here) Why hand Worcester-Hereford to Turbos?

You don't even need to buy hybrid trains to run the mostly electrified route as they already run on the (much-less electrified) route currently!

I'm pointing this out as it shows how warped you are when it comes to the idea that hybrid trains exist. Not only is your desire to fully electrify routes so services don't have to run diesels better served by wiring Birmingham suburban routes than Oxford-Coventry, but it's not even necessary anyway!

Warwick - Leamington would be a phase 2 job, with potentially Stratford UA - Warwick being a phase 2A, and phase 3 was to cover both approaches to Snow Hill from the east, as well as Kiddy (Worcester to Kiddy would get as part of phase 4 as part of the Cotswold services returning to Hereford, and the Cheltenhams running from Shrub Hill up to Stourbridge/a new station at Brierley Hill).

Sure, but I'm working on the assumption that Birmingham suburban electrification happens before your Stratford/Coventry to Oxford/Bicester 'phase 2', and so naturally Stratford - Warwick - Leamington would be swapped should the order of the phases swap.

And given your aversion to hybrid trains, why on earth did you end phase 3 at Kidderminster and thus not do the full route to Worcester? Are you proposing run a third of the stopping service through Birmingham as diesels and the rest as electric? Or are we looking at Worcestershire shuttles here? Even more bizarre as you have already wired up Worcester itself as part of phase 2 under your plan!

It was my thinking that the Voyagers could then run over the NE/SW route doubled up, or even replace HSTs at Scotrail!

They very well could (I'd assumed they would have been cascaded down to the XC regional routes), however if you are XC getting new stock, they'd be hybrid as more flexible for the franchise - even if they keep the Voyagers and run them doubled up.

And once this is grasped, then we can look at the case for Leamington-Banbury-Oxford electrification rationally (Coventry-Leamington will be Birmingham suburban, and electrified for those reasons, in the timescales involved, according to the regional aspirations for the Coventry corridor) rather than having "Manchester-Bournemouth needs to be fully electric" as the overriding dogma driving notions of what electrification is more important north of the Ridgeway.

Suburban electrification has massive advantages: acceleration gains, removal of diesel fumes from large urban areas, busy lines, easier to get the whole route converted. Electrifying through Banbury is infill - it makes a lot more sense when the urban stuff either side is done.

 

[HSTEd]

Again: If having a short section of adjacent track with a different electrification is something that pushes back electrification of the Birmingham suburban routes, why isn't it a problem for the London suburban routes?

Four rail electrification that has not be configured for interworking with NR third rail systems is much less problematic for integration with an AC traction system than the tram style electrification at the Birmingham end.

LU electrification has no return current through the rails at all.
The normal earthing problems are far less troublesome and there are no electrolytic corrosion problems to worry about.

 

[Bald Rick]

Four rail electrification that has not be configured for interworking with NR third rail systems is much less problematic for integration with an AC traction system than the tram style electrification at the Birmingham end.

LU electrification has no return current through the rails at all.
The normal earthing problems are far less troublesome and there are no electrolytic corrosion problems to worry about.

Agreed.

Also the issue with return currents are related to the peak power flow, and the total amount of power over time. With the Urbos 3 having a max power of 1MW, which they use sparingly, and a maximum frequency of 15tph total, it’s a rather different prospect to 3MW of Class 700 very 75 seconds, which is the problem between Blackfriars and City TL.

 

[satters]

Upgrading the Chiltern route should definitely be an aspiration, there was demand warranting both LMS and GWR routes between Birmingham and London in the past, and there is even more demand now,
Upgrading what there is, and reopening what was closed should be the plan for many reasons, and if it were done directly instead of by private contracts it need not be so expensive

 

[si404]

Four rail electrification that has not be configured for interworking with NR third rail systems is much less problematic for integration with an AC traction system than the tram style electrification at the Birmingham end.

LU electrification has no return current through the rails at all.
The normal earthing problems are far less troublesome and there are no electrolytic corrosion problems to worry about.

I did think this would probably be the case. My reason for asking the question was more about seeing whether it was valid technical reasons or just the tail of XC wagging the dog driving the idea that Banbury-Leamington should be electrified before the Birmingham suburban parts of the corridor.

There were mentions of both in the first response to my asking why the rural bit before the urban bit, but - especially given how short and simple this reply is - the responding but not really engaging with the question about the difference between Snow Hill to Jewellery Quarter vs Finchley Road to Neasden, but talking lots about XC, makes it look like tail wagging dog.

 

[MarkyT]

I did think this would probably be the case. My reason for asking the question was more about seeing whether it was valid technical reasons or just the tail of XC wagging the dog driving the idea that Banbury-Leamington should be electrified before the Birmingham suburban parts of the corridor.

There were mentions of both in the first response to my asking why the rural bit before the urban bit, but - especially given how short and simple this reply is - the responding but not really engaging with the question about the difference between Snow Hill to Jewellery Quarter vs Finchley Road to Neasden, but talking lots about XC, makes it look like tail wagging dog.

Discontinuous electrification with on-board batteries allows the quickest time to decarbonisation. Most mileage in easy rural areas could be tackled first with some further fill in as desired later in the more difficult urban areas, allowing time to resignal, rebuild structures, modify adjacent railway systems as required etc. Trains built with large batteries initially might have their storage capacity reduced after a few years, as the proportion of wired mileage on typical diagrams increases. This could coincide with typical battery replacement timescales as they age and degrade, reducing the cost of such work.

 

[cle]

The Watford Junction Met extension would have been the perfect excuse to divert all Met services there (north of Harrow) with a coordinated Chiltern AC project to Aylesbury and Chesham.

EWR, the missing link really is the stretch between Aylesbury VP and Winslow, could that ever be viable?

And on the mainline, a full programme of reinstating the platform loops and four tracks, to make continuous segments would help immensely. Not least brand new units capable of hitting line speed (which could also be reviewed) much sooner - 15 mins from Birmingham on a service calling 4-5 times isn’t so bad on an electrification project, the GWML has seen better to Cardiff. Yes 125 and further, but also flatter. And lower speeds yield higher percentage savings, so it could accumulate in a different way.

 

[The Planner]

The platform loops were short, and any train being overtaken is going to need a good 5 minute dwell.

 

[CyrusWuff]

As much as I'd like to see pure DMUs eliminated from Marylebone ASAP, I suspect the phasing would look something closer to this:

Phase 1 : Oxford - Leamington Spa - Coventry/Solihull - Birmingham New Street (as part of CrossCountry core electrification work)
Phase 2a : Snow Hill Lines and Stratford-upon-Avon branch
Phase 2b : Oxford - Bicester South Junction (as part of EWR electrification)
Phase 3a : Marylebone - Aynho Junction/Aylesbury (via Princes Risborough), Marylebone - Harrow-on-the-Hill and Amersham - Aylesbury Vale Parkway (Bay)
Phase 3b : Aylesbury Vale Parkway (Through Line) - Claydon (for EWR)

Though not necessarily in that order! The aim being to get as much as possible tacked on to other projects, so it falls somewhere else on the money-go-round, thereby improving the BCR.

 

[JonathanH]

Phase 1 : Oxford - Leamington Spa - Coventry/Solihull - Birmingham New Street (as part of CrossCountry core electrification work)

How would that be phase 1 and deliver a better BCR than the electrification of the services at Marylebone itself. Even a hypothetical 2tph Manchester to Reading electric service means losing links to Bournemouth and Yorkshire / the North East.

Phase 2a : Snow Hill Lines and Stratford-upon-Avon branch

The Snow Hill locals spread too far to offer a concise electrification project - clearly there is 6tph from Tyseley to Stourbridge, 4tph at Kidderminster and 3tph to Whitlocks End / Dorridge but quite a lot of route mileage beyond that.

I think that suggests that Marylebone is the more obvious place to start but even then it is a lot of route mileage to do before a material number of services can be converted and I guess that is the problem - any electrification of the Marylebone routes is a pretty material undertaking - ie of the scale of the Great Western electrification.

The aim being to get as much as possible tacked on to other projects, so it falls somewhere else on the money-go-round, thereby improving the BCR.

I'm not convinced that it works like that. The other projects do not necessarily have high BCRs in their own right.

 

[HSTEd]

With the HS2 reconstruction, will their be any space at Euston at all?
Diverting the Chiltern Main Line trains to there would allow Marylebone to be taken over by London Underground and converted into an overflow terminus for an expanded Met to Aylesbury.

Pity there arent more than two approach lines into Marylebone.
As far as I can tell there is a mess of tunnels but I dont know if there is continuous space for four tracks throughout.

That way you could split the terminus into a Met side and a vestigal National Rail side.

 

[The Planner]

With the HS2 reconstruction, will their be any space at Euston at all?
Diverting the Chiltern Main Line trains to there would allow Marylebone to be taken over by London Underground and converted into an overflow terminus for an expanded Met to Aylesbury.

Depends when you mean, but probably not, as soon as phase 1 opens then I suspect the redevelopment would start of the rest of the station including reducing the platforms further for phase 2. You cannot get to Euston easily from the Chilterns anyway, so you are trying to get a service onto the reliefs at West Ealing (nearly impossible with the Crossrail timetable) and then at Willesden West London (again, pretty difficult). What you really need is a confirmed plan at OOC for them.

 

[D365]

What you really need is a confirmed plan at OOC for them.

Indeed, I was under the impression that OOC will become a second Chiltern terminus.

 

[The Planner]

Indeed, I was under the impression that OOC will become a second Chiltern terminus.

Still not confirmed if it will happen, plenty of plans with it on in various forms.

 

[mr_jrt]

Pity there arent more than two approach lines into Marylebone.
As far as I can tell there is a mess of tunnels but I dont know if there is continuous space for four tracks throughout.

As I understand it, there are tunnels for 7 tracks at the southern end under Lords (two double track and one triple track), and it appears they made it at least some way from Marylebone at one time:

A number of shorter tunnels were backfilled into a single longer tunnel over the years, which may have lost the ability to have more tracks throughout - but there was originally room for 7 tracks to Wellington Road, though north of there the tunnel was only ever two tracks, and two across the WCML, though there was a second double track portal constructed on the far end by Finchley Road.

https://maps.nls.uk/geo/explore/#zoom=19&lat=51.52580&lon=-0.16520&layers=173&b=1

 

[MarkyT]

As I understand it, there are tunnels for 7 tracks at the southern end under Lords (two double track and one triple track), and it appears they made it at least some way from Marylebone at one time:

A number of shorter tunnels were backfilled into a single longer tunnel over the years, which may have lost the ability to have more tracks throughout - but there was originally room for 7 tracks to Wellington Road, though north of there the tunnel was only ever two tracks, and two across the WCML, though there was a second double track portal constructed on the far end by Finchley Road.

https://maps.nls.uk/geo/explore/#zoom=19&lat=51.52580&lon=-0.16520&layers=173&b=1

Those spare tunnels near the terminus are now blocked by foundations of a large hotel building. At Finchley Rd the extra portal extends about 100m to a dead end and only ever had some temporary track in it during construction. It's reasonable to assume the GCR probably had aspirations to widen the terminus and its approaches using these facilities, but it clearly never proved necessary.

 

[corfield]

There does seem to be spare land where it crosses the NLL, but yes, widening is completely impossible.

The best option would be to give the Met fasts to Chiltern and cutback/widen the Met to deconflict.

Then AC OHLE the lines to Aylesbury and High Wycombe (PRisborough?). That deals with the stoppers, and allows expansion of the commuter services.

On the Aylesbury side the service is slow and not really commutable - yet Aylesbury has gone to 70k population and is already en route for 125k, and has decent light industry but concerns on employment, so fast services in would really support that.

It is also really noticeable that prices are far lower than equivalent WCML and CML towns the same distance - reflecting the poorer london route.

I get Amersham etc want the direct Met services but that is where an interchange is needed.

From Aylesbury as EWR gets electrified then to that is fairly easy.

Doing to Banbury at the same time pulls in another service pattern and ties in with Oxford-Bicester-EWR.

After that switch to Birmingham and do all the Snow Hill lines until finally join them up.

End to end express stuff may disappear with HS2 but this line has seen that thought before and semi-express still offers the vital long distance options to intermediate stops to either end.

In terms of OOC, is this a published plan? I thought that had died long ago as a Crossrail arm? Will OOC have capacity for xtph down the New North Line from High Wycombe? (That then would be a logical electrification route).

 

[swt_passenger]

...In terms of OOC, is this a published plan? I thought that had died long ago as a Crossrail arm? Will OOC have capacity for xtph down the New North Line from High Wycombe? (That then would be a logical electrification route).

This isn’t about Crossrail through running onto Chiltern, it’s about additional Chiltern terminus platforms at Old Oak Common, with some sort of cross platform interchange onto Crossrail.

 

[MarkyT]

This isn’t about Crossrail through running onto Chiltern, it’s about additional Chiltern terminus platforms at Old Oak Common, with some sort of cross platform interchange onto Crossrail.

Unlikely to be cross platform I'd say, but convenient nonetheless.

 

[The Planner]

Unlikely to be cross platform I'd say, but convenient nonetheless.

One of the plans Ive seen has it cross platform.

 

[corfield]

Ahh that makes more sense. Is there room - OOC is going to be seriously busy with HS2 and Overground adding to Cross Rail and GW!

What would provide these services? The High Wycombe stoppers? Bicester and beyond express? Or MK via Aylesbury? The latter would be interesting as it opens a lot of connections up.

Does this release Marylebone capacity? Could it then take over Outer Met? (i’m assuming if Chiltern had the Met fasts they could invest in increasing speed etc to give a better service to the outer Chiltern stations?

 

[norbitonflyer]

As to the question why Marylebone is the last diesel outpost in London, it was for many years proposed for closure, with trains diverted to Paddington (from the Wycombe line) and Baker Street (from the Aylesbury line). Unthinkable now, with the increased use of both those termini. Then it was proposed (in the 1980s) to be part of Crossrail, again closing Marylebone. Even at privatisation it was seen as a backwater.

 

[cle]

Surely OOC would be 1-2 longer bays, as the Crossrail platforms would need to be pretty wide anyway without up to 8 car bays cutting into their western end. Haven't seen anything with their own island, but of course that would be ideal.

My thinking with the platform loops (the Ruislips through to Denham, for instance) would be to connect the shorter loops to become dynamic ones/shorter 4 track sections.

I would think the initial phase would have to be Marylebone to Oxford. That would remove at least 4tph instantly, including those with the most metro/stops - with Banbury next.

 

[MarkyT]

One of the plans Ive seen has it cross platform.

In both directions?

 

[swt_passenger]

Ahh that makes more sense. Is there room - OOC is going to be seriously busy with HS2 and Overground adding to Cross Rail and GW!

What would provide these services? The High Wycombe stoppers? Bicester and beyond express? Or MK via Aylesbury? The latter would be interesting as it opens a lot of connections up.

Does this release Marylebone capacity? Could it then take over Outer Met? (i’m assuming if Chiltern had the Met fasts they could invest in increasing speed etc to give a better service to the outer Chiltern stations?

The NR route summary suggests it is 4 “additional” tph.

Access to HS2 at Old Oak Common is a central part of the Chilterns strategy, offering up to four additional trains per hour into Old Oak and Park Royal, an area of considerable regeneration in West London. This destination also offers key connectivity links to high speed, inter-city and Crossrail services.

https://cdn.networkrail.co.uk/wp-co...-East-West-Rail-Strategy-summary-document.pdf

Current published plans for EWR have removed the possibility of through trains from Milton Keynes across Aylesbury. Obviously that can change in the long term but it’s not something you should be expecting.

 

[philthetube]

TBH, I'd be more inclined to hand over the Met's fast lines to NR, and have OHLE all the way from Aylesbury to Neasden South. Met loses service from Moor Park to Amersham/Chesham, or a bit of new track is laid from Watford south junction to a rebuilt Rickmansworth station with a full-size bay to retain that link. Capacity at Marylebone is the biggest issue, but if Chiltern gets a platform or two at OOC then perhaps enough capacity could be freed up for things to work out.

Doing things that way then means NR can make a case for lengthening platforms and improving line speeds and thus try to draw passengers away from railheading to the WCML or the Chiltern mainline to free up capacity there.

I might be wrong but I seem to remember that because of the relatively tight turns on the Chesham branch there's a limit to the length of cartridge suitable for the route.

Handing over the fasts to Chiltern would cause issues with track capacity into Marylebone and capacity for onward travel for passengers from Marylebone.

 

[mr_jrt]

I've been having a read and it suggests the Bubble cars have served the branch, which would suggest it was ok for 20m units.

 

[HSTEd]

Depends when you mean, but probably not, as soon as phase 1 opens then I suspect the redevelopment would start of the rest of the station including reducing the platforms further for phase 2. You cannot get to Euston easily from the Chilterns anyway, so you are trying to get a service onto the reliefs at West Ealing (nearly impossible with the Crossrail timetable) and then at Willesden West London (again, pretty difficult). What you really need is a confirmed plan at OOC for them.

Well in my ideal world we would be closing both Paddington and Marylebone, and demolishing most of Somers Town to concentrate them all onto the Euston King's Pancreas complex.